1. Field of the Invention
This invention relates to trenchers and an attachment including the trencher adjustably mounted on the extensible boom of a truck mounted excavator.
2. Description of the Prior Art
Trenching devices attached to various motor driven vehicles may be seen in U.S. Pat. Nos. 3,044,194, 3,266,179, 3,398,471 and 3,710,472.
In U.S. Pat. No. 3,044,194 and 3,266,179, tractors support position and operate trenchers.
In U.S. Pat. No. 3,044,194, the trencher is closely coupled to the tractor while in U.S. Pat. No. 3,266,179 a boom and boom extension support the trencher on the tractor.
In U.S. Pat. No. 3,710,472 a boom mounted on a truck carries a dipper stick which in turn has a trencher and a bucket affixed thereto.
In U.S. Pat. No. 3,398,471, a trencher and auger are mounted on a tractor.
The present invention relates to a trencher attachment which in addition to adjustably positioning a trencher supplies the motion necessary to actuate the trencher and a screw-type conveyor positioned transversely of the attachment for removing excavated material away from the excavation. More importantly, the trencher attachment of the present invention can be adjustably mounted on the end of a telescopically extensible boom of a truck mounted excavator such as for example the hydraulic excavator said under the trademark GRADALL manufactured by the Gradall Company of New Philidelphia, Ohio.
The trencher attachment of the present invention replaces the bucket normally used on the telescopically extensible boom of the GRADALL device.
The prior art references neither disclose or suggest the novel trencher attachment of the present invention.